DE 91 13 007 U1 discloses a piston-type accumulator for the actuation of the bulk material discharge device in railway cars. The hydraulic installation provided for such railway cars has at least one hydraulic pump driven by an additional driving wheel set arrangement, which pumps a loading fluid stream into the piston-type accumulator during movement of the railway car. If the adjusted operation pressure is then attained in the accumulator in this manner, the shut-off device causes the loading fluid stream to be reversed in direction to pass through the bypassing conduit without pressure to the reservoir connection of the hydraulic installation. Therefore, the stream flows back into the fluid storage container.
With that piston-type accumulator, the combination of the traditional pressure accumulator and the shut-off device for the loading fluid stream with the required associated operating device leads to a costly structure, producing excessively high manufacturing and maintenance costs. The plurality of structural component parts which are movable relative to one another increases the wear on parts.
DE-A-1 185 025 discloses a piston-type accumulator for the actuation of the bulk commodities discharge device on railway cars. The hydraulic installation provided with such railway cars has at least one hydraulic pump powered by an additional set of wheels. The pump pumps a loading fluid stream into the piston-type accumulator during the movement of the railway car. If the adjusted operation pressure is then attained in the accumulator in this manner, the shut-off device causes the loading fluid stream to be reversed through the bypassing conduit without pressure to the reservoir connection of the hydraulic installation and to flow in reverse into the fluid storage reservoir.